Eluting device for nuclide generators

ABSTRACT

Device for eluting nuclide generators comprising a nuclide generator, conveying means, container for eluting agent, and eluate container, wherein the container for the eluting agent, the eluate container and the conveying means are connected with the nuclide generator by conduits, the conveying means are mounted between the container for the eluting agent and the eluate container and the conveying means comprise a control mechanism which permits to convey freely chosen amounts of eluate into the eluate container.

United States Patent [1 1 Strecker et al.

ELUTING DEVICE FOR NUCLIDE GENERATORS Inventors: Helmut Strecker, Seeheim;

Karl-Heinz Tetzlaff, Kelkheim. Taunus, both of Germany 1 1 Aug. 5, 1975 3.156.532 11/1964 Doering 23/272 3,5](L271 5/1970 Emneus 23/272 3535085 10/1971) Shumute i. 23/267 R 3.561932 2/1971 Truvermun 23/272 $620,675 I 1/1971 Olson i i 23/267 B 3.7741135 11/1973 Lit! i w 4 i i i i v v 23/272 R 3.774036 11/1973 Gerhurt 252/3011 R OTHER PUBLICATlONS Gillette, Review of Radioisotopes Program 1964 May 1965, O.R.NL.3802, pages 8 and 9.

PI'iHKU) [:It'umineF-A. Louis Monacell Assistant EtmuiuerS. J. Emery [30] J l iz gl g Priority Dam 65 Attorney, Agent, or Firm-Curtis, Morris & Sufford u y ermuny -2 A CT [52] [1.5. C1 1. 23/252 R; 23/267 R; 23/2726 R; FSTRA 252/30] R Device for elutmg nuchde generators compnsmg a nu [51] Int. Cl H Bold 11/02: (Elf 5/00. G21}, 5/02 clide generator conveying means. container for elut- [58] Fidd of Search 23/267 R 272 2716 R ing agent, and eluute container, wherein the container 23/252 R 259 267 B 2521/3011 for the eluting agent. the eluute container and the con- 250/430 435 veying means are connected with the nuclide generator by conduits, the conveying means are mounted he- [56] References Cited tween the container for the eluting agent and the eluate container and the conveying means comprise 11 UNITED STATES PATENTS control mechanism which permits to convey freely 2.123212 7/l938 Scholler 23/2 chosen amounts of cluzite into the eluute container 2.427.042 9/1947 Bowman 23/272 2 968,72| 1/1961 Shapiro 1. 23/272 4 Claims, 8 Drawing Figures J L 35,2 1 n i l 6 21 i I 18 L I '4 i o I- II 7 i z 11 r s I A i l 1 1 2 i l r I/ 11h J A i i 32 5 5 3 I I a 4 s -J- 2- L-Ll PATENTED AUB 5 FIGA PATENTEU AUG 1975 SHEET ELUTING DEVICE FOR NUCLIDE GENERATORS The present invention relates to a device for eluting nuclide generators.

Nuclide generators serve to apply radio-nuclides of short life time in medicine and technics. A radio-active mother nuclide of longer life time produces a short lived daughter nuclide which can repeatedly be cluated by a separating column. By a closed sterile system composed of eluting agent, column, eluate container and transfer system eluates are obtained which can be injected or are suitable for making injectable prepara tions.

Devices are known wherein the eluate container is positioned above the nuclide generator which is eluated by the hydrostatic pressure of the eluting agent. The elution rate depends on the generator resistance and, therefore, it is not constant. In this manner fractional elution is however possible.

In other known devices the eluate container is evacuated so that the eluting agent is sucked through the column. The flowing rate of the eluting agent is not constant and fractional elution is difficult.

Devices have also become known in which the eluting agent is pressed through the nuclide generator by means of an injection syringe. The repeated piercing of the generator seal involves the danger of unsterility. The elution rate depends on the resistance of the column and the pressure of the piston.

Finally, devices have been proposed in which the eluting agent is pressed through the generator by a pis ton pump, wherein the danger of unsterility is given by the moving piston of the pump.

In order to overcome the aforesaid difficulties in the known devices, the invention provides a device for eluting nuclide generators wherein the container for the eluting agent, the container for the eluate and the conveying means are connected with the nuclide generator by conduits, the conveying means are positioned between the container for the eluting agent and the container for the eluate, and the conveying means com prise a control device allowing of conveying freely cligible amounts of eluate into the eluate container.

According to a variant of the device of the invention the conveying means are arranged between the container for the eluting agent and the nuclide generator.

Alternatively, the conveying means can be installed between the nuclide generator and the eluate container.

It proved advantageous to branch off a conduit to the conveying means from the conduit connecting the nuclide generator with the eluate container. It is of advantage to seal the conveying means hermetically with respect to the outside and to operate it electrically. Nuclide generator, container for eluting agent, conveying means and eluate container are preferably connected with one another by means of plug connections. The eluate container should be placed in a transparent casing protecting against radiation.

It has also been found that an especially good eluate, a greater variability of the eluate properties and an optinium working safety are obtained by using a tube pump. The tube pump has the property to convey, independent of the flow resistance of the column, a constant mass flow. The constant mass flow produces a uniform activity distribution. Thus the minimum amount of eluting agent required for an adequate yield can be exactly ascertained and hence the column may be kept small. The good reproducibility further permits to find with certainty the desired activity concentration with fractional elution. Owing to the exact dosing, additional amounts to ensure a minimum yield need not be used. The high pump pressure permits to use finegrained and hence very active ion exchangers and other active substances for the column. With the high permissible pressure loss in the column greater ratios of col' umn length to column cross section can be used. Finally, the high pump pressure allows of installing filters.

Owing to the uniform and adjustable pumping velocity even with counter pressure it is possible to eluate directly into injection syringes or into conduit systems or into the organism. The pump also permits to reconduct the eluate to the column so that fractional cluation can be carried out without loss in activity and with simple operation. The recycling of the eluate can also be used for a complete mixing of the activity. This results in an even activity concentration and permits the direct filling of syringes with determined activity amounts and the withdrawal of activity needed.

In spite of the greater variability of the eluate properties the device of the invention offers a great security as regards the course of operation and protection against radiation.

The device of the invention will now be described in further detail and by way of example with reference to the accompanying drawings wherein:

FIG. I is a simplified representation of the mode of operation of the device.

FIG. 2 is a sectional view of the device according to the invention.

FIG. 3 is a top view of the device according to the invention.

FIG. 4 is a fragmentary sectional view of a variant of the device as shown in FIG. 2.

FIG. 5 illustrates a mode of execution of the shut off valves.

FIG. 6 represents the tube pump with lubricating means.

FIG. 7 is a fragmentary sectional view of the generator connection.

FIG. 8 is a fragmentary sectional view of a special embodiment of the supply section of the device shown in FIG. 2.

A container I for the eluting agent, preferably a bag of plastic material provided with an impervious junction 2 which can be pierced by a hollow needle is connected with a conduit 4 by an injection needle 3. Conduit 4 has a fix point 5 to which a conduit 8 is connected leading to the conveying device 9. As conveying devices rotary pumps with small dead volume and hermetically sealed with respect to the outside can be used, for example tube pumps. diaphragm pumps, or bellows pumps, a statorless tube pump being especially suitable. The preferably three cornered pump impeller carries an absorbent layer 10, for example a sponge, tissue, or hide, for a lubricating liquid, for for example glycerol, which continuously lubricates the pump hose 8 preferably made of silicone rubber or a similar elastic material.

From the conveying device the current of conveyed fluid is passed over a second fix point 11, which provides for the right tension of the tube together with fix point 5, and through conduit 12 it arrives at the entrance of nuclide generator [3. The nuclide generator is positioned in a protecting casing 14. Conduit 12 is connected to the nuclide generator by an injection needle which may be curved. The junctions of nuclide generator 13 are provided with piercable stoppers made of an elastic material. To protect the injection needle 15 against unsterility and contamination with the shield material a hose [6 is pulled over which is pushed back when the needle is prieked through the stopper. The outlet of nuclide generator 13 has the same construction as the inlet. The protecting casing 14 need not be opened. From the nuclide generator 13 a conduit l7 leads to eluate container 2] via injection needle as eluate container an injection flask with evacuation tube 22 may be used. Conduit 4 may additionally be provided with a branching 6, formed, for example. of a valve stopper 5a, simultaneously serving as fix point 5, with two connections. Conduit 6 is connected with conduit 1711 via a second valve stopper 7 and conduit 17a is connected with eluate container 21 by way of valve stopper 7, injection needle 18, conduit 19 and injection needle 20. As eluate container there may also be used an injection syringe 26 directly linked up with injection needle 18 via valve stopper 7. With pulled out injection needle [8 the eluate is recycled to the entrance of the nuclide generator through conduit 6 by means of conveying device 9. With the aid of valve stopper 5a a nuclide generator linked to the system of conduits can be charged with the mother nuclide or. if the conveying device fails, it can be eluated by an injection syringe. Instead of valve stopper 7 two valves 24 and 25 can be used, for example tube clips.

The conveying device 9 is driven by electric means. The power supply. for example battery 27, can be installed in the device. The revolution of the pump impeller or the stroke frequency of the pump is firmly connected by way of speed reducers with a preselection device 28 switching off the conveying device after the de sired amount has been conveyed. The speed reduction can be effected. for example. by a gear connected with a selecting disk with a plate cam on the same shaft which actuates a switch. The selecting disk can be set to the desired amount by a safety clutch or a friction gear. The conveying device is switched on by means of a push-button switch.

lt proved advantageous to separate the driving and control mechanisms from the conveying device and to install them in a separate casing. the dosing head 30. which is set in an unchangeablc position on top of the potshaped supply section 31. Dosing head and conveying device are then connected by a suitable coupling. for example toothed wheels. drivers and magnets. When the dosing head 30 is taken off, supply section 31 containing parts I to 11 and in part conduits l2 and 17a readily accessible from above and also laterally at the conveying device. Supply section 3] is provided with an additional disk-shaped radiation shield 32. The lateral and lower additional protection against radiation is ensured by a pot-shaped container 33, on which the entire device rests. To protect the eluate container 2] from radiation, it is placed in a transparent con tainer 34, for example of lead glass, or a container with double walls the clearing of which is filled with a solution of elements of high atomic number. Container 34 is closed by a detachable cover 35 having at least one small boring for injection needles.

in a particularly advantageous variant of the device of the invention as shown in FIG. 8 the supply section 31 is firmly connected with the protecting casing 36 containing the nuclide generator. All parts i to [7a are mounted in this combination preferably ready for instant use. ln this case the nuclide generator and the container for the eluting agent are provided with stationary connections. The container 36 is attached to a disk 37 in tight and solid manner. By means ofa tension ring 38 and a sealing 39 a hood 40 is clamped on the said disk. After having inserted the tight transportable unit into container 33, removed hood 40 and mounted dosing head 30 on top it is ready for use.

The following examples serve to illustrate the inven' tion.

EXAMPLE 1 In a nuclide generator consisting of a column filled with 6 grams ofaluminium oxide and having 1 milliliter of dead space at each end closed by a rubber stopper radioactive Tc is to be separated from Mo emanating 50 mCi. With 11 ml of physiological sodium chlo ride solution almost the entire amount of 45 mCi Tc capable of being washed out can be eluated. To obtain a higher activity concentration, for example. 42.3 mCi Tc can be washed out with 8.3 milliliters. corresponding to an activity concentration of 10.2 mCi/ml. To this effect the device as shown in FIGS. 2, 3 and 5 is used. 8.3 Milliliters are set on selecting disk 28 and push-button switch 29 is actuated, whereupon eluate is pumped by tube pump 9 into the shielded eluate container 21. After conveyance of 8.3 milliliters the pump is automatically switched off. The elution is terminated. When needed the eluate can be taken from eluate container 21 by an injection syringe.

EXAMPLE 2 Out of a nuclide generator as described in Example I, 6 injection syringes of high activity and ready for immediate use are to be filled within a period of 5 hours at equal intervals.

First at the selecting disk 28 a high amount by vol time is set. for example 23 milliliters. Next. without connecting eluate container 21 to valve stopper 7, push-button switch 29 is actuated whereby a mixing process is started since the eluate flows back through conduit 6 to the entrance ofthe nuclide generator. The uniform activity concentration would permit to take with several injection syringes up to about of the activity capable of being washed out. As it is only desired, however, to take 6.3 mCi the required amount is set on selecting disk 28, injection syringe 26 is pushed through valve stopper 7 and push-button switch 29 is actuated. in this manner 6 times 6.2 mCi are obtained. Prior to each filling of the syringe a mixing is performed.

If this example were carried out in the manner described in Example 1, 6 times 4.25 mCi could be taken. In both cases the activity concentration is approximately equal. With the first extraction the activity concentration according to Example 2 is by 7% higher and with the last extraction by 7% lower than in Example 1.

Hence. when proceeding as described in Example 2, 487r more activity can be brought into action in the given case under approximately the same conditions.

What is claimed is:

l. A device for cluting nuclide generators comprising a radiation shield container having an open top. a nuclide generator positioned in said container; a housing removably mounted on said container adjacent said open top and including a container for an eluting agent, a container for receiving eluate from said generator, a plurality of conduits connecting said eluting agent container through said open top to said generator and said generator to said eluate container. and pump means mounted in said housing and operatively connected to said conduits for pumping liquid therethrough; said pump means including selectively operable control means for limiting operation of said pump to pump only a predetermined amount of eluate into the eluate container said pump means being installed in said housing between the container for the eluting agent and the container for said nuclide generator and being operatively associated with the conduit therebetween'. and said conduit connecting the nuclide generator with the eluate container including a branching conduit connccted to the conduit connecting the nuclide generator with the container for eluting agent. thereby to provide a recirculating path between said housing and said generator.

2. The device of claim 1, wherein said pump means comprises an electrically driven pump which is hermetically sealed in said housing.

3. The device ofclaim 1, wherein the nuclide generator. the container for the eluting agent. the pump means and the eluate container are connected with one another by socket connections associated with said conduits.

4. The device of claim 1. wherein the cluate container is in a transparent radiation protecting container. 

1. A DEVICE FOR ELUTING NUCLIDE GENERATORS COMPRISING A RADIATION SHIELD CONTAINER HAVING AN OPEN TOP, A NUCLIDE GENERATOR POSITIONED IN SAID CONTAINER, A HOUSING REMOVABLY MOUNTED ON SAID CONTAINER ADJACENT SAID OPEN TOP AND INCLUDING A CONTAINER FOR AN ELUTING AGENT, A CONTAINER FOR RECEIVING ELUATE FROM SAID GENERATOR, A PLURALITY OF CONDUITS CONNECTING SAID ELUTING AGENT CONTAINER THROUGH SAID OPEN TOP TO SAID GENERATOR AND SAID GENERATOR TO SAID ELUATE CONTAINER, AND PUMP MEANS MOUNTED IN SAID HOUSING SAID OPERATIVELY CONNECTED TO SAID CONDUITS FOR PUMPING LIQUID THERETHROUGH, SAID PUMP MEANS INCLUDING SELECTIVELY OPERABLE CONTROL MEANS FOR LIMITING OPERATION OF SAID PUMP TO PUMP ONLY A PREDETERMINED AMOUNT OF ELUATE INTO THE ELUATE CONTAINER SAID PUMP MEANS BEING INSTALLED IN SAID HOUSING BETWEEN THE CONTAINER FOR THE ELUTING AGENT AND THE CONTAINER FOR SAID NUCLIDE GENERATOR AND BEING OPERATIVELY ASSOCIATED WITH THE CONDUIT THEREBETWEEN, AND SAID CONDUIT CONNECTING THE NUCLIDE GENERATOR WITH THE CONELUATE CONTAINER INCLUDING A BRANCHING CONDUIT CONNECTED TO THE CONDUIT CONNECTING THE NUCLIDE GENERATOR WITH THE CONTAINER FOR ELUTING AGENT, THEREBY TO PROVIDE A RECIRCULATING PATH BETWEEN SAID HOUSING AND SAID GENERATOR.
 2. The device of claim 1, wherein said pump means comprises an electrically driven pump which is hermetically sealed in said housing.
 3. The device of claim 1, wherein the nuclide generator, the container for the eluting agent, the pump means and the eluate container are connected with one another by socket connections associated with said conduits.
 4. The device of claim 1, wherein the eluate container is in a transparent radiation protecting container. 